Noise analysis in a seeded four-wave mixing process generated in a photonic crystal fiber pumped by a chirped pulse.

Four-wave mixing is investigated when chirped pump and signal pulses are injected in a photonic crystal fiber. The shot-to-shot stability of the amplified coherent signal was measured by using the dispersive Fourier transform method and compared with numerical simulations. We highlight that the signal-to-noise ratio (SNR) of the pulsed signal increases with the injected power and show that it is not deteriorated through the amplification when the fiber optical parametric amplifier is strongly saturated. The SNR of the signal remains nearly constant after the amplifier.

Spectral correlation of four-wave mixing generated in a photonic crystal fiber pumped by a chirped pulse.

We report the spectral distribution of the parametric process generated in a photonic crystal fiber pumped by a chirped pulse. The spectral correlation of four-wave mixing has been measured using the dispersive Fourier transform method. From statistical analysis of multiple shot-to-shot spectral measurements, the spectral correlation between the signal and idler photons reveals physical insights into the particular portion of the pump spectrum responsible for generating the four-wave mixing. Therefore, the shape of the correlation map indicates directly the temporal and spectral links between the signal and the pump, which are highly important to design a four-wave mixing based amplifier.

12 THz flat gain fiber optical parametric amplifiers with dispersion varying fibers.

We report a fiber-optic parametric amplifier with ultra-broad and flat gain band by using a longitudinally tailored optical fiber. The parametric amplifier has been designed from realistic numerical simulations combined with an inverse algorithm to obtain a flat and wide gain band through fiber dispersion management. We experimentally report ~12 THz gain bandwidth on the Stokes side of the pump with a gain ripple as low as 7 dB and a mean gain up to ~60 dB. Experimental results show good agreement with numerical predictions for different pump powers and wavelength detuning.

Ultra-broadband fiber optical parametric amplifier pumped by chirped pulses.

We numerically and experimentally demonstrate ultra-broadband fiber optical parametric amplification in a microstructured fiber pumped by stretched short pulses. The chirped pump pulse induces a temporally spread spectral gain suitable for optical parametric chirped pulse amplification in fibers. Numerical simulation shows ~45 dB flat gain with more than 70 nm bandwidth, allowing sub-35 fs pulse amplification around 1 µm with reduced gain narrowing. This amplification principle is experimentally confirmed by measuring the instantaneous spectral gain band and related chirp.

Flat-top picosecond pulses generated by chirped spectral modulation from a Nd:YLF regenerative amplifier for pumping few-cycle optical parametric amplifiers.

In this paper we present an optically synchronized Nd:YLF regenerative amplifier optimized for use as a preamplifier in a few-cycle optical parametric chirped pulse amplification pump laser. In the pump amplification process we employ a combination of spectral modulation and chirping in order to control and optimize the temporal shape of the pulses. We report on a comparative study of two methods for generating near-flat-top or custom real-time variable-shaped pump pulses using either controlled chirp and shaping of the spectrum of the pulses seeding a regenerative amplifier or intracavity spectral filtering to broaden the gain bandwidth of the system. We show that in addition to minimizing gain narrowing and B-integral, the efficiency of the cascaded nonlinear processes of the parametric amplifiers can be increased.

Correlation between multiple modulation instability side lobes in dispersion oscillating fiber.

We investigate numerically and experimentally the spectral correlation between multiple modulation instability (MI) side lobes in a dispersion oscillating fiber. By leveraging the dispersive Fourier transformation, we acquire instantaneous spectra and investigate the energy correlation between individual MI sidebands through scattergrams. We found that conjugate MI side lobes are strongly correlated while other combinations experience a very low degree of correlation, revealing that parametric processes related to each side lobe pair act quasi-independently.

High-energy temporally shaped nanosecond-pulse master-oscillator power amplifier based on ytterbium-doped single-mode microstructured flexible fiber.

We present a versatile master-oscillator power amplifier system at 1053 nm in the few-nanoseconds regime meeting the high-level requirements of high-power laser facility front ends. Thanks to temporal shaping, more than 1.5 mJ pulse energy at 1 kHz with an excellent optical signal-to-noise ratio has been obtained in a single-mode 40 µm core flexible fiber.

High-gain fiber, optical-parametric, chirped-pulse amplification of femtosecond pulses at 1 µm.

Fiber-based optical-parametric chirped-pulse amplification is reported at 1µm in a microstructured fiber in the femtosecond regime. The signal has been highly stretched by an Öffner triplet and then amplified with an all-fiber, pulsed-pump, fiber optical-parametric amplifier. More than 30dB gain has been achieved over 8.3nm, and the amplified signal has been recompressed.

Experimental demonstration of optical parametric chirped pulse amplification in optical fiber.

We experimentally demonstrate optical parametric chirped pulse amplification for the first time (to our knowledge) in a completely integrated all-fiber optical system. A single chirped fiber Bragg grating, achieving both the stretching and compression stages, is combined with a cw-pumped fiber optical parametric amplifier. As a proof of principle, we demonstrate the amplification of picosecond Fourier-transform-limited pulses at 1550nm.

Factorization of numbers with the temporal Talbot effect: optical implementation by a sequence of shaped ultrashort pulses.

We report on the successful operation of an analogue computer designed to factor numbers. Our device relies solely on the interference of classical light and brings together the field of ultrashort laser pulses with number theory. Indeed, the frequency component of the electric field corresponding to a sequence of appropriately shaped femtosecond pulses is determined by a Gauss sum which allows us to find the factors of a number.

Detection and quantification of multiple molecular species in mainstream cigarette smoke by continuous-wave terahertz spectroscopy.

Continuous-wave terahertz spectroscopy by photomixing is applied to the analysis of mainstream cigarette smoke. Using the wide tunability of the source, spectral signatures of hydrogen cyanide (HCN), carbon monoxide (CO), formaldehyde (H2CO), and water (H2O) have been observed from 500 to 2400 GHz. The fine spectral purity allows direct concentration measurement from the pure rotational transitions of HCN and CO. The quantification of the measurement was validated by the means of a calibration gas containing CO. The potential of this technique for trace gas detection is demonstrated with an estimated detection limit of HCN equal to 9 parts in 10(6).